1. Field of the Invention
The present invention relates to a recording apparatus having recording means for outputting input information such as characters or image onto the recording medium, and an information processing system having said recording apparatus as output means, such as a copying machine, a facsimile, a printer, a word processor, and a personal computer.
2. Related Background Art
Conventionally, recording apparatuses which perform the recording on the recording medium (hereinafter simply referred to as the recording sheet) such as paper, clothe plastic sheet, OHP sheet, etc., have been proposed in the form capable of mounting a recording head of various recording systems including, for example, wire dot system, thermal system, thermal transfer system, and ink jet system.
Amount such recording apparatuses, a recording apparatus comprising a recording head of the ink jet system in which the recording is performed on the recording sheet by discharging the ink through discharge ports (nozzles) arranged on the recording elements (hereinafter referred to as an ink jet recording apparatus), known as the non-impact recording with low noise, can attain high density and fast recording operation.
The ink jet recording apparatus takes the configuration corresponding to the specific functions or service conditions of the system to which the apparatus is applied. Typically, the ink jet recording apparatus comprises a carriage having a recording head and an ink tank mounted thereon, conveying means for conveying the recording sheet, and control means for controlling them.
And the recording head for discharging ink droplets through a plurality of discharge ports is scanned serially in a direction (main scan direction) orthogonal to a conveying direction (sub-scan direction) of the recording sheet, while the recording sheet is conveyed intermittently (pitch feed) by an amount equal to the recording width when not recording. By using the recording head having a number of nozzles for discharging the ink arranged linearly in the sub-scan direction, the recording can be performed for a width corresponding to the number of nozzles every time the recording head scans once over the recording sheet.
Also, the ink jet recording apparatus has the low running cost, can be made more compact, and is easy to deal with the color image recording by using color inks. In particular, a recording apparatus of the line type using recording means of the line type having a number of discharge ports arranged in the width direction of the recording sheet has the capability of the faster recording.
From the above reasons, the ink jet recording apparatus has been utilized and produced on a commercial scale as output means of the information processing system, for example, a printer useful for a copying machine, a facsimile, an electronic typewriter, a word processor, an output terminal such as a workstation, or a handy or portable printer provided in a personal compubter, a host computer, an optical disk unit, or a video device.
The recording elements of the ink jet recording means, i.e., energy generating means for generating the energy to discharge the ink, may include those of using an electromechanical converter such as a piezo-electric element, those of directing radiation of electromagnetic wave such as a laser to generate heat, and discharge liquid droplets by the action of that heat, and those of heating the liquid by the employment of electricity-heat converting element having a heating resistor.
Among them, a recording head of the ink jet recording system of discharging the liquid by the use of heat energy can perform the recording with high resolution, because the liquid discharge ports can be arranged at high density. In particular, a recording head using electricity-heat converting element as energy generating means is beneficial, because the recording head can be easily made more compact, can make more effective use of the merits of the IC technology or micro-process technology which has found remarkable progress of the technology and improved reliability in the recent semiconductor field, is easy to make high density packaging, and have the low manufacturing cost.
An ink tank for supplying the ink to the recording head is substantially comprised of an ink absorbing member, a vessel within which the ink absorbing member is accommodated, and a lid member for sealing the vessel.
The recording head as above described has two types including a chip type of having an ink tank integrally formed therewith and a type of having an ink tank detachably coupled. In either case, the positioning between the recording head and the ink tank, or the positioning between the head cartridge having these members integrated and the carriage, is an important item relating to the print quality. One of such positioning means employs a fit hole and a fit pin, thereby allowing for the positioning correctly.
It is to be noted that the recording apparatus on which the head cartridge is mounted has a head recovery device as described below to protect the recording head.
First, the head recovery device will be described.
The head recovery device is disposed at one end of the movement passage of the recording head, e.g., at a site opposed to a home position. The head recovery device is operated by the driving force of a motor via a transmission mechanism to make the capping of the recording head. Ink suction (suction recovery) is performed by appropriate suction means (e.g., a suction pump) provided within the head recovery device in connection with the capping of the recording head with a cap portion of the head recovery device, thereby performing a discharge recovery processing of removing the thickened ink within the discharge ports by compulsorily discharging the ink through the discharge ports. Also, the recording head is protected by making the capping after the completion of the recording. Such discharge recovery processing may be performed when the power is turned on, when the recording head is replaced, and when the recording operation is interrupted beyond a fixed time.
Next, a wiping unit will be described.
The wiping unit is disposed on the side face of the head recovery device, and has a blade as a wiping member formed of silicone rubber. The blade is held in a cantilevered form by a blade holding member, and activated by the motor as well as the transmission mechanism, like the head recovery device, to be engageable with the discharge face of the recording head. Thus, at an appropriate timing in the recording operation of the recording head, or after the discharge recovery processing using the head recovery device, the blade is protruded into the movement passage of the recording head to wipe off the dew, the wet or the dust on the discharge face of the head along with the movement of the head.
In this way, the ink jet recording apparatus can stabilize the ink discharge performance by using the head recovery device and the wiping unit. Accordingly, in mounting or demounting such a member (e.g., a head cartridge having the recording head and the ink tank integrated) on or from the carriage, it is necessary to take care not to place the nozzle face of the recording head into contact with the recovery device or the platen to deform the recording head or the recovery device, as well as other members.
The following constructions of mounting the head cartridge are provided including:
(1) Directly pressing a flexible cable within the carriage.
(2) Providing a recess portion for receiving the flexible cable within the head cartridge and mounting the head cartridge in the proximity of the carriage.
(3) Using a carriage having the flexible cable attached, movable up and down, to mount the head cartridge by moving up the carriage, and secure it therein by lowering the carriage to make the printing.
In any way, it is important for the high printing accuracy to secure physically the electrical contact between the flexible cable and the head cartridge, and to position the head cartridge with the carriage at high precision and reliably.
In the recent ink jet recording apparatuses, an ink tank of large capacity to allow for a great amount of recording is often used as a replacement tank. When a head cartridge having such ink tank is used, a mounting structure of turning the ink tank about a first positioning member into abutment with a second positioning member is often utilized to effect the easy coupling and the correct positioning.
However, the above conventional recording apparatus may cause a deformation or breakage of the recording head due to the problems on the construction as described below, even if the user carefully performs the coupling operation of the head cartridge.
One of the problems is that no appropriate coupling means conforming with the structure of the ink jet cartridge to be mounted is provided on the recording apparatus main unit.
In order to avoid such deformation as above mentioned, it is conceived that the head coupling position may be provided outside the cap position and the recording area, but it is required to make the apparatus size larger from the necessity of reserving a space thereof, opposed to the requirement of compact apparatus. On the other hand, if the head replacement position is provided within the recording area, there was a risk that the top end (face plane) of the recording head might rub against the guide of recording sheet conveying means, upon coupling the recording head, because the distance from the nozzle top end of the recording head to the recording surface of the recording sheet is as narrow as about 1 mm to 2 mm to assure the recording image quality. In this case, the recording quality may be degraded if the head face plane is damaged.
In the construction of mounting the head cartridge by directly pressing a flexible cable within the carriage, or by turning the head cartridge, there was the problem that the flexible cable might be damaged due to friction, and the flexible cable be worn. This problem will also occur in the head cartridge of the type providing a recess portion for receiving the flexible cable within the head cartridge and mounting the head cartridge in proximity of the carriage, due to friction between the recess portion and the flexible cable.
In the construction of having a carriage having the flexible cable attached, movable up and down, to mount the head cartridge by moving up the carriage, and secure it therein by lowering the carriage to make the printing, there is a problem that the mechanism becomes more complex, and the apparatus is larger in size.